1. Field of the Invention
The present invention relates to a filament winding apparatus equipped with a hoop winding device and a helical winding device and, in particular, to an improved hoop winding device.
2. Description of the Related Art
When forming a pressure container by a filament winding method, a fiber bundle is hoop wound or helical wound on a mandrel to form a reinforcement layer (see Japanese Laid-Open Patent Publication No. 10-119138, paragraphs 0022 to 0023, FIG. 1). In a conventional general filament winding apparatus, the fiber bundle is hoop wound or helical wound with one type of winding head.
As described above, hoop winding and helical winding are carried out with one type of winding head in a conventional filament winding apparatus, and thus a great amount of time is inevitably required for the process of winding the fiber bundle on the mandrel, which becomes a great barrier in manufacturing pressure containers and the like. In particular, since a great amount of time is required for hoop winding, it is desirable to increase the speed of the hoop winding process.